Web/API/WebSocket/open event

The open event is fired when a connection with a WebSocket is opened.

Bubbles	No
Cancelable	No
Interface	Event
Event handler property	onopen

Examples

// Create WebSocket connection.
const socket = new WebSocket('ws://localhost:8080');

// Connection opened
socket.addEventListener('open', (event) => {
  socket.send('Hello Server!');
});

Specifications

Specification	Status
HTML Living StandardThe definition of 'WebSocket open' in that specification.	Living Standard

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
open event	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE ?	Opera Full support Yes	Safari ?	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support Yes

Legend

Full support  

Full support

Compatibility unknown  

Compatibility unknown

See also

• WebSocket: close event
• WebSocket: error event
• WebSocket: message event
• Writing WebSocket client applications

WebSocket: open event by Mozilla Contributors is licensed under CC-BY-SA 2.5.